Fall 2019 SPO600 Weekly Schedule

This is the schedule and main index page for the SPO600 Software Portability and Optimization course for Fall 2019.

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This page is in the process of being updated from a previous semester's content. It is not yet updated for Fall 2019. Do not rely on the accuracy of this information until this warning is removed.

Schedule Summary Table

This is a summary/index table. Please follow the links in each cell for additional detail which will be added below as the course proceeds -- especially for the Deliverables column.

Week	Week of...	Class I Tuesday 1:30-3:15 Room B1024	Class II Friday 11:40-1:25 Room K1263	Deliverables (Summary - click for details)
1	Sep 2	Introduction / How is code accepted into an open source project? (Lab 1) / Computer Architecture Overview	Compiled C Lab (Lab 2)	Set up accounts.
2	Sep 9	Intro to Assembler / Using Makefiles	Assembler Lab (Lab 3)	Blog your conclusion to Labs 1 and 2, and blog about your initial work on Lab 3.
3	Sep 16	Sysadmin for Devs	Assembler Lab (Lab 3) Continued	Blog about Lab 3.
4	Sep 23	Computer Resources and Performance / Baseline Builds / Benchmarking and Profiling	Software Build Lab (Lab 4)	Blog your Lab 4 results.
5	Sep 30	Binary Representation of Data	Algorithm Selection (Lab 5) / Inline Assembler	Blog your lab 5 results.
6	Oct 7	SIMD and Vectorization / Inline Assembler]	Investigation: Inline Assembler (Lab 6)	Blog your lab 6 results.
7	Oct 14	Projects!	Project selection	Catch up on any missed labs, blog about your project selection progress.
	Oct 21	Reading Week
8	Oct 28	Intrinsics and SIMD	Project Hacking	Blog blog about your project.
9	Nov 4	Atomics	Project Hacking	Blog about your project.
10	Nov 11	Memory Ordering / Barriers / Acquire-Release Semantics	Project Hacking	Blog about your project.
11	Nov 18	ifunct	Project Hacking	Blog about your project.
12	Nov 25	Projects	Project Hacking	Blog about your project.
13	Dec 2	Projects	Wrap-up Discussion	Blog about your project.
Exam	Dec 9	Exam Week - No exam in this course!

Evaluation

Category	Percentage	Evaluation Dates
Communication	20%	September (Oct 6 - 5%), October (Nov 10 - 5%), November (Dec 3 - 5%), end of course (Dec 12 - 5%).
Quizzes	10%	May be held during any class, usually at the start of class. A minimum of 5 one-page quizzes will be given. No make-up/retake option is offered if you miss a quiz. Lowest 3 scores will not be counted.
Labs	10%	See deliverables column above. All labs must be submitted by Dec 12, but it is best if you stay on top of the labs and submit according to the table above.
Project work	60%	3 stages: 15% (Nov 6), 20% (Nov 21), 25% (Dec 12).

Week 1

• Labour day - no Class I this week

Week 1 - Class II

Introduction to the Problems

Porting and Portability

• Most software is written in a high-level language which can be compiled into machine code for a specific computer architecture. In many cases, this code can be compiled for multiple architectures. However, there is a lot of existing code that contains some architecture-specific code fragments written in architecture-specific high-level code or in Assembly Language.
• Reasons that code is architecture-specific:
  • System assumptions that don't hold true on other platforms
    • Variable or word size
    • Endianness
  • Code that takes advantage of platform-specific features
• Reasons for writing code in Assembly Langauge include:
  • Performance
  • Atomic Operations
  • Direct access to hardware features, e.g., CPUID registers
• Most of the historical reasons for including assembler are no longer valid. Modern compilers can out-perform most hand-optimized assembly code, atomic operations can be handled by libraries or compiler intrinsics, and most hardware access should be performed through the operating system or appropriate libraries.
• A new architecture has appeared: AArch64, which is part of ARMv8. This is the first new computer architecture to appear in several years (at least, the first mainstream computer architecture).
• At this point, most key open source software (the software typically present in a Linux distribution such as Ubuntu or Fedora, for example) now runs on AArch64. However, it may not run as well as on older architectures (such as x86_64).

Benchmarking and Profiling

Benchmarking involves testing software performance under controlled conditions so that the performance can be compared to other software, the same software operating on other types of computers, or so that the impact of a change to the software can be gauged.

Profiling is the process of analyzing software performance on finer scale, determining resource usage per program part (typically per function/method). This can identify software bottlenecks and potential targets for optimization.

Optimization

Optimization is the process of evaluating different ways that software can be written or built and selecting the option that has the best performance tradeoffs.

Optimization may involve substituting software algorithms, altering the sequence of operations, using architecture-specific code, or altering the build process. It is important to ensure that the optimized software produces correct results and does not cause an unacceptable performance regression for other use-cases, system configurations, operating systems, or architectures.

The definition of "performance" varies according to the target system and the operating goals. For example, in some contexts, low memory or storage usage is important; in other cases, fast operation; and in other cases, low CPU utilization or long battery life may be the most important factor. It is often possible to trade off performance in one area for another; using a lookup table, for example, can reduce CPU utilization and improve battery life in some algorithms, in return for increased memory consumption.

Most advanced compilers perform some level of optimization, and the options selected for compilation can have a significant effect on the trade-offs made by the compiler, affecting memory usage, execution speed, executable size, power consumption, and debuggability.

Build Process

Building software is a complex task that many developers gloss over. The simple act of compiling a program invokes a process with five or more stages, including pre-proccessing, compiling, optimizing, assembling, and linking. However, a complex software system will have hundreds or even thousands of source files, as well as dozens or hundreds of build configuration options, auto configuration scripts (cmake, autotools), build scripts (such as Makefiles) to coordinate the process, test suites, and more.

The build process varies significantly between software packages. Most software distribution projects (including Linux distributions such as Ubuntu and Fedora) use a packaging system that further wraps the build process in a standardized script format, so that different software packages can be built using a consistent process.

In order to get consistent and comparable benchmark results, you need to ensure that the software is being built in a consistent way. Altering the build process is one way of optimizing software.

Note that the build time for a complex package can range up to hours or even days!

General Course Information

• Course resources are linked from the CDOT wiki, starting at http://wiki.cdot.senecacollege.ca/wiki/index.php/SPO600 (Quick find: This page will usually be Google's top result for a search on "SPO600").
• Coursework is submitted by blogging.
• Quizzes will be short (1 page) and will be held without announcement at any time, generally at the start of class. There is no opportunity to re-take a missed quiz, but your lowest three quiz scores will not be counted, so do not worry if you miss one or two.
  • Students with test accommodations: an alternate monthly quiz is available in the Test Centre. See the professor for details.
• Course marks (see Weekly Schedule for dates):
  • 60% - Project Deliverables
  • 20% - Communication (Blog and Wiki writing)
  • 20% - Labs and Quizzes (10% labs - completed/not completed; 10% for quizzes - lowest 3 scores not counted)
• All classes will be held in an Active Learning Classroom -- you are encouraged to bring your own laptop to class. If you do not have a laptop, consider signing one out of the Learning Commons for class, or using a smartphone with an HDMI adapter.
• For more course information, refer to the SPO600 Weekly Schedule (this page), the Course Outline, and SPO600 Course Policies.

Course and Setup: Accounts, agreements, servers, and more

• SPO600 Communication Tools
• Winter 2018 SPO600 Participants page
• Key generation for SSH to the SPO600 Servers.
• Student Agreement

How open source communities work

• Code Review Lab (Lab 1) as homework.

Computer Architecture

• Computer Architecture overview (see also the Computer Architecture Category)
• A first look at the x86_64 and AArch64 Architectures and ISA
  • Register file comparison
  • Instruction encoding
  • ELF
  • Procedure calling conventions

Reference

• Computer Architecture and Computer Architecture Category

Week 1 Deliverables

1. Course setup:
   1. Set up your SPO600 Communication Tools - in particular, set up a blog and add it to Planet CDOT (via the Planet CDOT Feed List).
   2. Add yourself to the SPO600 Participants page (leave the projects columns blank).
   3. Generate a pair of keys for SSH and email the public key to your professor, so that he can set up your access to the class servers.
2. Optional (strongly recommended): Set up a personal Fedora system.
3. Optional: Purchase an AArch64 development board (such as a 96Boards HiKey or Raspberry Pi 3. If you use a Pi, install a 64-bit Linux operating system on it, not a 32-bit version).

Week 2

Week 2 - Class I

• Sysadmin for Developers
• Building Code
  • Make and Makefiles
  • Code Building Lab (Lab 2)

Week 2 - Class II

• Compiler Operation
  • Stages of Compilation
    1. Preprocessing
    2. Compiling
    3. Assembling
    4. Linking
• Analyzing compiler output
  • Disassembly
• Compiled C Lab (Lab 3)

Week 2 Deliverables

• Blog your conclusion to the Code Review Lab (Lab 1)
• Blog the results and conclusion from the Compiled C Lab (Lab 2)
• Blog the results and conclusion from the Compiled C Lab (Lab 3)

Week 3

Week 3 - Class I

• Make and Makefiles
• Assembly Language
• Assembler Lab (Lab 4)

Week 3 - Class II

• Assembler Lab (Lab 4) Continued...

Week 3 Deliverables

• Blog about Lab 4.

Week 4

Week 4 - Class I

• Assembler Lab (Lab 4) Wrap-up...
• Binary Representation of Data
  • Integers
  • Fixed-point
  • Floating-point
  • Sound
  • Graphics
  • Compression techniques
    • Huffman encoding / Adaptive arithmetic encoding
    • Repeated sequence encoding (1D, 2D, 3D)
    • Decomposition
    • Pallettization
    • Psychoacoustic and psychovisual compression

Week 4 - Class II

• Algorithm Selection Lab (Lab 5)

Week 4 Deliverables

• Blog your results to Lab 4

Week 5

Week 5 - Class I

Note: Your prof is away!

• Investigate various tools available for Profiling
  • Ensure that you know how to use gprof
  • Ensure that you know how to use at least one other Linux profiling tool
  • Blog about it, including the example of profiling the sound scaling programs from Lab 5

Week 5 - Class II

• SIMD and Auto-vectorization
• Inline Assembler
• Vectorization Lab (Optional lab - recommended)

Week 5 Deliverables

• Blog your Profiling investigation results
• Optional: Blog about the Vectorization Lab if you performed it

Week 6

Week 6 - Class I

• Thanksgiving -- enjoy time with your friends and family!
  • No class

Week 6 - Class II

• Note: Your prof is away
  • Room is available to collaborate if desired -- AV unlock code is 2598
• Perform the Inline Assembler Lab (Lab 6)

Week 6 Deliverables

• Blog your results to the Inline Assembler Lab (Lab 6)

Week 7

Week 7 - Class I

• Discussion

Week 7 - Class II

• Discussion

Week 7 Deliverables

• Wrap up any labs not yet completed.

Week 8

Week 8 - Class I

• Fall 2018 SPO600 Project

Week 8 - Class II

• Project Discussion

Week 8 Deliverables

• Blog about your project.